In a random access wireless communication system, a communication link between an access terminal and an access point is not continuous. An access terminal can register with an access point and can remain in an idle state. The access terminal can transition from the idle state to an active state to initiate an active communication link. In the active state, the access terminal is able to receive information from the access point as well as transmit information to the access point.
For the majority of the time, the access terminal remains in the idle state, awaiting the transition into the active state. The access terminal is typically a mobile device that operates from batteries stored within the device. The access terminals can conserve energy and extend the battery operated run time by transitioning to a low power state, often referred to as a sleep state. However, in many instances, the access terminal cannot immediately transition from the sleep state to the active state.
The access terminal typically does not have the ability to monitor information transmitted by the access points when it is in the sleep state. Therefore, the access terminals typically periodically transition to an idle state to monitor for messages from the access points.
Some wireless communication systems incorporate quick paging channels that are used by the access points to indicate the presence of a paging message to an access terminal. The paging message can direct the particular access terminal to transition to the active state to support active information exchange.
The wireless communication system can assign a particular bit in a particular message as the quick paging bit for a particular access terminal or group of access terminals. The access terminals can then awaken from a sleep state for a duration that is sufficient to receive the quick paging bit. If the access terminal detects an active quick paging bit, the access terminal becomes aware of a subsequent paging message and can remain in or transition to the idle state to monitor for the paging message. Conversely, if the access terminal fails to detect its assigned quick paging bit, it assumes that there are no imminent paging messages directed to it. In this manner, the access terminals can minimize the time that they need to be in an idle mode, thereby maximizing the time that can be dedicated to a lower power sleep state.
For example, both CDMA2000 and WCDMA wireless communication systems have a quick paging channel that allows a mobile station to periodically monitor an assigned quick paging bit to detect a presence of a page. When a page is sent to the mobile station, the base station sets the corresponding bit to ‘1’. If the bit is set, the mobile station, which represents the access terminal, listens to the full page. However, if the access terminal improperly detects the bit to be ‘0’, or determines an erasure indicating the inability to discern the state of the received bit, then a missed page occurs. Therefore, there is a need to reduce the probability of a missed page. However, there remains the need to maintain or increase the battery powered operational time for mobile devices.